vendor/llvm/llvm-trunk-r290819

1 files changed, 224 insertions, 0 deletions

diff --git a/include/llvm/Bitcode/BitcodeReader.h b/include/llvm/Bitcode/BitcodeReader.h
new file mode 100644
index 000000000000..9e042b17241f
--- /dev/null
+++ b/include/llvm/Bitcode/BitcodeReader.h
@@ -0,0 +1,224 @@
+//===-- llvm/Bitcode/BitcodeReader.h - Bitcode reader ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This header defines interfaces to read LLVM bitcode files/streams.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_BITCODE_BITCODEREADER_H
+#define LLVM_BITCODE_BITCODEREADER_H
+
+#include "llvm/Bitcode/BitCodes.h"
+#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/IR/ModuleSummaryIndex.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/ErrorOr.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include <memory>
+
+namespace llvm {
+  class LLVMContext;
+  class Module;
+
+  // These functions are for converting Expected/Error values to
+  // ErrorOr/std::error_code for compatibility with legacy clients. FIXME:
+  // Remove these functions once no longer needed by the C and libLTO APIs.
+
+  std::error_code errorToErrorCodeAndEmitErrors(LLVMContext &Ctx, Error Err);
+
+  template <typename T>
+  ErrorOr<T> expectedToErrorOrAndEmitErrors(LLVMContext &Ctx, Expected<T> Val) {
+    if (!Val)
+      return errorToErrorCodeAndEmitErrors(Ctx, Val.takeError());
+    return std::move(*Val);
+  }
+
+  /// Represents a module in a bitcode file.
+  class BitcodeModule {
+    // This covers the identification (if present) and module blocks.
+    ArrayRef<uint8_t> Buffer;
+    StringRef ModuleIdentifier;
+
+    // The bitstream location of the IDENTIFICATION_BLOCK.
+    uint64_t IdentificationBit;
+
+    // The bitstream location of this module's MODULE_BLOCK.
+    uint64_t ModuleBit;
+
+    BitcodeModule(ArrayRef<uint8_t> Buffer, StringRef ModuleIdentifier,
+                  uint64_t IdentificationBit, uint64_t ModuleBit)
+        : Buffer(Buffer), ModuleIdentifier(ModuleIdentifier),
+          IdentificationBit(IdentificationBit), ModuleBit(ModuleBit) {}
+
+    // Calls the ctor.
+    friend Expected<std::vector<BitcodeModule>>
+    getBitcodeModuleList(MemoryBufferRef Buffer);
+
+    Expected<std::unique_ptr<Module>> getModuleImpl(LLVMContext &Context,
+                                                    bool MaterializeAll,
+                                                    bool ShouldLazyLoadMetadata,
+                                                    bool IsImporting);
+
+  public:
+    StringRef getBuffer() const {
+      return StringRef((const char *)Buffer.begin(), Buffer.size());
+    }
+
+    StringRef getModuleIdentifier() const { return ModuleIdentifier; }
+
+    /// Read the bitcode module and prepare for lazy deserialization of function
+    /// bodies. If ShouldLazyLoadMetadata is true, lazily load metadata as well.
+    /// If IsImporting is true, this module is being parsed for ThinLTO
+    /// importing into another module.
+    Expected<std::unique_ptr<Module>> getLazyModule(LLVMContext &Context,
+                                                    bool ShouldLazyLoadMetadata,
+                                                    bool IsImporting);
+
+    /// Read the entire bitcode module and return it.
+    Expected<std::unique_ptr<Module>> parseModule(LLVMContext &Context);
+
+    /// Check if the given bitcode buffer contains a summary block.
+    Expected<bool> hasSummary();
+
+    /// Parse the specified bitcode buffer, returning the module summary index.
+    Expected<std::unique_ptr<ModuleSummaryIndex>> getSummary();
+  };
+
+  /// Returns a list of modules in the specified bitcode buffer.
+  Expected<std::vector<BitcodeModule>>
+  getBitcodeModuleList(MemoryBufferRef Buffer);
+
+  /// Read the header of the specified bitcode buffer and prepare for lazy
+  /// deserialization of function bodies. If ShouldLazyLoadMetadata is true,
+  /// lazily load metadata as well. If IsImporting is true, this module is
+  /// being parsed for ThinLTO importing into another module.
+  Expected<std::unique_ptr<Module>>
+  getLazyBitcodeModule(MemoryBufferRef Buffer, LLVMContext &Context,
+                       bool ShouldLazyLoadMetadata = false,
+                       bool IsImporting = false);
+
+  /// Like getLazyBitcodeModule, except that the module takes ownership of
+  /// the memory buffer if successful. If successful, this moves Buffer. On
+  /// error, this *does not* move Buffer. If IsImporting is true, this module is
+  /// being parsed for ThinLTO importing into another module.
+  Expected<std::unique_ptr<Module>> getOwningLazyBitcodeModule(
+      std::unique_ptr<MemoryBuffer> &&Buffer, LLVMContext &Context,
+      bool ShouldLazyLoadMetadata = false, bool IsImporting = false);
+
+  /// Read the header of the specified bitcode buffer and extract just the
+  /// triple information. If successful, this returns a string. On error, this
+  /// returns "".
+  Expected<std::string> getBitcodeTargetTriple(MemoryBufferRef Buffer);
+
+  /// Return true if \p Buffer contains a bitcode file with ObjC code (category
+  /// or class) in it.
+  Expected<bool> isBitcodeContainingObjCCategory(MemoryBufferRef Buffer);
+
+  /// Read the header of the specified bitcode buffer and extract just the
+  /// producer string information. If successful, this returns a string. On
+  /// error, this returns "".
+  Expected<std::string> getBitcodeProducerString(MemoryBufferRef Buffer);
+
+  /// Read the specified bitcode file, returning the module.
+  Expected<std::unique_ptr<Module>> parseBitcodeFile(MemoryBufferRef Buffer,
+                                                     LLVMContext &Context);
+
+  /// Check if the given bitcode buffer contains a summary block.
+  Expected<bool> hasGlobalValueSummary(MemoryBufferRef Buffer);
+
+  /// Parse the specified bitcode buffer, returning the module summary index.
+  Expected<std::unique_ptr<ModuleSummaryIndex>>
+  getModuleSummaryIndex(MemoryBufferRef Buffer);
+
+  /// isBitcodeWrapper - Return true if the given bytes are the magic bytes
+  /// for an LLVM IR bitcode wrapper.
+  ///
+  inline bool isBitcodeWrapper(const unsigned char *BufPtr,
+                               const unsigned char *BufEnd) {
+    // See if you can find the hidden message in the magic bytes :-).
+    // (Hint: it's a little-endian encoding.)
+    return BufPtr != BufEnd &&
+           BufPtr[0] == 0xDE &&
+           BufPtr[1] == 0xC0 &&
+           BufPtr[2] == 0x17 &&
+           BufPtr[3] == 0x0B;
+  }
+
+  /// isRawBitcode - Return true if the given bytes are the magic bytes for
+  /// raw LLVM IR bitcode (without a wrapper).
+  ///
+  inline bool isRawBitcode(const unsigned char *BufPtr,
+                           const unsigned char *BufEnd) {
+    // These bytes sort of have a hidden message, but it's not in
+    // little-endian this time, and it's a little redundant.
+    return BufPtr != BufEnd &&
+           BufPtr[0] == 'B' &&
+           BufPtr[1] == 'C' &&
+           BufPtr[2] == 0xc0 &&
+           BufPtr[3] == 0xde;
+  }
+
+  /// isBitcode - Return true if the given bytes are the magic bytes for
+  /// LLVM IR bitcode, either with or without a wrapper.
+  ///
+  inline bool isBitcode(const unsigned char *BufPtr,
+                        const unsigned char *BufEnd) {
+    return isBitcodeWrapper(BufPtr, BufEnd) ||
+           isRawBitcode(BufPtr, BufEnd);
+  }
+
+  /// SkipBitcodeWrapperHeader - Some systems wrap bc files with a special
+  /// header for padding or other reasons.  The format of this header is:
+  ///
+  /// struct bc_header {
+  ///   uint32_t Magic;         // 0x0B17C0DE
+  ///   uint32_t Version;       // Version, currently always 0.
+  ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
+  ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
+  ///   ... potentially other gunk ...
+  /// };
+  ///
+  /// This function is called when we find a file with a matching magic number.
+  /// In this case, skip down to the subsection of the file that is actually a
+  /// BC file.
+  /// If 'VerifyBufferSize' is true, check that the buffer is large enough to
+  /// contain the whole bitcode file.
+  inline bool SkipBitcodeWrapperHeader(const unsigned char *&BufPtr,
+                                       const unsigned char *&BufEnd,
+                                       bool VerifyBufferSize) {
+    // Must contain the offset and size field!
+    if (unsigned(BufEnd - BufPtr) < BWH_SizeField + 4)
+      return true;
+
+    unsigned Offset = support::endian::read32le(&BufPtr[BWH_OffsetField]);
+    unsigned Size = support::endian::read32le(&BufPtr[BWH_SizeField]);
+    uint64_t BitcodeOffsetEnd = (uint64_t)Offset + (uint64_t)Size;
+
+    // Verify that Offset+Size fits in the file.
+    if (VerifyBufferSize && BitcodeOffsetEnd > uint64_t(BufEnd-BufPtr))
+      return true;
+    BufPtr += Offset;
+    BufEnd = BufPtr+Size;
+    return false;
+  }
+
+  const std::error_category &BitcodeErrorCategory();
+  enum class BitcodeError { CorruptedBitcode = 1 };
+  inline std::error_code make_error_code(BitcodeError E) {
+    return std::error_code(static_cast<int>(E), BitcodeErrorCategory());
+  }
+
+} // End llvm namespace
+
+namespace std {
+template <> struct is_error_code_enum<llvm::BitcodeError> : std::true_type {};
+}
+
+#endif